It has caused CI failures.
* d0cd0866d8
Disable GC during rb_objspace_reachable_object_p
* 89cef1c56b
Version guard for [Feature #15974]
* 796eeb6339.
Fix up [Feature #15974]
* 928260c2a6.
Warn in verbose mode on defining a finalizer that captures the object
Various things can cause GC to occur when compaction is running, for
example resizing the object identity map:
```
frame #24: 0x000000010c784a10 ruby`gc_grey [inlined] push_mark_stack(stack=<unavailable>, data=<unavailable>) at gc.c:4311:42
frame #25: 0x000000010c7849ff ruby`gc_grey(objspace=0x00007fc56c804400, obj=140485906037400) at gc.c:4907
frame #26: 0x000000010c78f881 ruby`gc_start at gc.c:6464:8
frame #27: 0x000000010c78f5d1 ruby`gc_start [inlined] gc_marks_start(objspace=0x00007fc56c804400, full_mark=<unavailable>) at gc.c:6009
frame #28: 0x000000010c78f3c0 ruby`gc_start at gc.c:6291
frame #29: 0x000000010c78f399 ruby`gc_start(objspace=0x00007fc56c804400, reason=<unavailable>) at gc.c:7104
frame #30: 0x000000010c78930c ruby`objspace_xmalloc0 [inlined] objspace_malloc_fixup(objspace=<unavailable>, mem=0x000000011372a000, size=<unavailable>) at gc.c:9665:5
frame #31: 0x000000010c7892f5 ruby`objspace_xmalloc0(objspace=0x00007fc56c804400, size=12582912) at gc.c:9707
frame #32: 0x000000010c89bc13 ruby`st_init_table_with_size(type=<unavailable>, size=<unavailable>) at st.c:605:39
frame #33: 0x000000010c89c5e2 ruby`rebuild_table_if_necessary [inlined] rebuild_table(tab=0x00007fc56c40b250) at st.c:780:19
frame #34: 0x000000010c89c5ac ruby`rebuild_table_if_necessary(tab=0x00007fc56c40b250) at st.c:1142
frame #35: 0x000000010c89c379 ruby`st_insert(tab=0x00007fc56c40b250, key=140486132605040, value=140485922918920) at st.c:1161:5
frame #36: 0x000000010c794a16 ruby`gc_compact_heap [inlined] gc_move(objspace=0x00007fc56c804400, scan=<unavailable>, free=<unavailable>, moved_list=140485922918960) at gc.c:7441:9
frame #37: 0x000000010c794917 ruby`gc_compact_heap(objspace=0x00007fc56c804400, comparator=<unavailable>) at gc.c:7695
frame #38: 0x000000010c79410d ruby`gc_compact [inlined] gc_compact_after_gc(objspace=0x00007fc56c804400, use_toward_empty=1, use_double_pages=<unavailable>, use_verifier=1) at gc.c:0:22
```
We *definitely* need the heap to be in a consistent state during
compaction, so this commit sets the current state to "during_gc" so that
nothing will trigger a GC until the heap finishes compacting.
This fixes the bug we saw when running the tests for https://github.com/ruby/ruby/pull/2264
pointers.
Instead of 4fe908c164, just locking the MJIT
worker may be fine for this case. And also we might have the same issue
in all `gc_compact_after_gc` calls.
rb_gc_finalize_deferred() is remained for compatibility with
C-extensions. However, this function is no longer working
from Ruby 2.4 (crash with SEGV immediately).
So remove it completely.
`heap_pages_sorted` includes eden and tomb pages, so we should not
use tomb pages for GC.compact (or we should move all of tomb pages
into eden pages). Now, I choose only eden pages. If we allow to
move Zombie objects (objects waiting for finalizers), we should
use both type of pages (TODO).
Fix debug output to dump more useful information on GC.compact
debugging.
check_rvalue_consistency_force() now accepts `terminate` flag
to terminate a program with rb_bug() or only print error message.
GC.verify_internal_consistency use this flag (== FALSE) to dump
all of debug output.
is_pointer_to_heap(obj) checks this obj belong to a heap page.
However, this function returns TRUE even if the page is tomb page.
This is re-commit of [712c027524].
heap_page_add_freeobj() should not use is_pointer_to_heap(), but
should check more explicitly.
GC.verify_internal_consistency() checks health of each RVALUE with
check_rvalue_consistency(). However, this function is enabled
only on debug environment (RGENGC_CHECK_MODE>1). So introduce
new function check_rvalue_consistency_force() and use it
in GC.verify_internal_consistency.
is_pointer_to_heap() checks if it is in valid pointer to the
RVALUE in any heap_page_body. However, it returns true if it
points tomb pages. This patch check it points to eden pages.
